Added setup connectivity warning

app/src/main/java/eu/faircode/email/FragmentSetup.java

@@ -31,6 +31,7 @@ import android.graphics.Paint;
 import android.graphics.Typeface;
 import android.graphics.drawable.Drawable;
 import android.net.ConnectivityManager;
+import android.net.Network;
 import android.net.Uri;
 import android.os.Build;
 import android.os.Bundle;
@@ -62,6 +63,7 @@ import java.util.List;
 public class FragmentSetup extends FragmentBase {
     private ViewGroup view;
 
+    private TextView tvNoInternet;
     private ImageButton ibHelp;
     private Button btnQuick;
     private TextView tvQuickNew;
@@ -127,6 +129,7 @@ public class FragmentSetup extends FragmentBase {
 
         // Get controls
 
+        tvNoInternet = view.findViewById(R.id.tvNoInternet);
         ibHelp = view.findViewById(R.id.ibHelp);
         btnQuick = view.findViewById(R.id.btnQuick);
         tvQuickNew = view.findViewById(R.id.tvQuickNew);
@@ -429,6 +432,7 @@ public class FragmentSetup extends FragmentBase {
                     : R.color.lightColorBackground_cards));
         }
 
+        tvNoInternet.setVisibility(View.GONE);
         btnIdentity.setEnabled(false);
         tvNoComposable.setVisibility(View.GONE);
 
@@ -517,6 +521,11 @@ public class FragmentSetup extends FragmentBase {
     public void onResume() {
         super.onResume();
 
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
+            ConnectivityManager cm = (ConnectivityManager) getContext().getSystemService(Context.CONNECTIVITY_SERVICE);
+            cm.registerDefaultNetworkCallback(networkCallback);
+        }
+
         // Doze
         Boolean ignoring = Helper.isIgnoringOptimizations(getContext());
 
@@ -553,6 +562,16 @@ public class FragmentSetup extends FragmentBase {
         }
     }
 
+    @Override
+    public void onPause() {
+        super.onPause();
+
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
+            ConnectivityManager cm = (ConnectivityManager) getContext().getSystemService(Context.CONNECTIVITY_SERVICE);
+            cm.unregisterNetworkCallback(networkCallback);
+        }
+    }
+
     @Override
     public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
         for (int i = 0; i < permissions.length; i++)
@@ -571,6 +590,28 @@ public class FragmentSetup extends FragmentBase {
         btnPermissions.setEnabled(!granted);
     }
 
+    private ConnectivityManager.NetworkCallback networkCallback = new ConnectivityManager.NetworkCallback() {
+        @Override
+        public void onAvailable(Network network) {
+            view.post(new Runnable() {
+                @Override
+                public void run() {
+                    tvNoInternet.setVisibility(View.GONE);
+                }
+            });
+        }
+
+        @Override
+        public void onLost(@NonNull Network network) {
+            view.post(new Runnable() {
+                @Override
+                public void run() {
+                    tvNoInternet.setVisibility(View.VISIBLE);
+                }
+            });
+        }
+    };
+
     public static class FragmentDialogDoze extends FragmentDialogBase {
         @NonNull
         @Override

app/src/main/res/layout/fragment_setup.xml

@@ -112,6 +112,22 @@
                     app:layout_constraintStart_toEndOf="@id/one"
                     app:layout_constraintTop_toTopOf="@id/one" />
 
+                <eu.faircode.email.FixedTextView
+                    android:id="@+id/tvNoInternet"
+                    android:layout_width="wrap_content"
+                    android:layout_height="wrap_content"
+                    android:layout_marginTop="12dp"
+                    android:drawableStart="@drawable/twotone_warning_24"
+                    android:drawablePadding="6dp"
+                    android:drawableTint="?attr/colorWarning"
+                    android:text="@string/title_no_internet"
+                    android:textAlignment="center"
+                    android:textAppearance="@style/TextAppearance.AppCompat.Small"
+                    android:textColor="?attr/colorWarning"
+                    app:layout_constraintEnd_toEndOf="parent"
+                    app:layout_constraintStart_toStartOf="parent"
+                    app:layout_constraintTop_toBottomOf="@id/title1" />
+
                 <ImageButton
                     android:id="@+id/ibHelp"
                     android:layout_width="48dp"
@@ -141,7 +157,7 @@
                     android:textStyle="bold"
                     app:layout_constraintEnd_toEndOf="parent"
                     app:layout_constraintStart_toStartOf="parent"
-                    app:layout_constraintTop_toBottomOf="@id/title1" />
+                    app:layout_constraintTop_toBottomOf="@id/tvNoInternet" />
 
                 <eu.faircode.email.FixedTextView
                     android:id="@+id/tvQuickRemarkMultiple"